When the first Avro 504 aircraft
were developed in 1913, they were designed for reconnaissance
and bombing for the Royal Flying Corps (RFC). These biplanes
were also used for anti-Zeppelin patrols carried out by the
Royal Naval Air Service.

The plane had a .303 calibre Lewis machine gun placed on the
upper wing, and could carry a rack that held four, 9.07 kilogram
bombs.

The Avro 504 was the first aircraft to carry out bombing runs
over Germany in 1914, but was also the first Allied aircraft to
be shot down in the war.

The early Avro 504s were used in the First World War as
bombers, but were soon removed from such duties, and continued
as Zeppelin interceptors flying for the Home Defence Force.